1. Field of the Invention
This invention pertains to a system and method for the extraction of magnesium, fresh water, chlorine and hydrogen from seawater, brines, salinated waters or other waste streams.
2. General Background
The production of magnesium from seawater, or other types of salinated water, is currently inefficient and environmentally unsound. Some attempts to produce magnesium from seawater include the use of open systems which heat a slurry until oxidation reduces it to its elemental components. Some such systems and methods are described as follows.
U.S. Pat. No. 5,124,012 issued to G. Berleyev, of Germany, on the application of F. Vomberg, discloses a process for the desalination of seawater by separating ions (Mg++, etc.) contained therein into two (2) separate solutions. At Column 5 thereof are chemical equations illustrating the production of magnesium hydroxide (Mg(OH).sub.2) and hydrogen gas (H.sub.2) from magnesium (Mg) and water (H.sub.2 O). But here, the slurry of calcium and magnesium is heated in an open system until oxidation occurs and then reduced to elemental materials with a hydrogen reducing flame.
U.S. Pat. No. 3,250,691 issued to T. T. Broun, Jr., et al., discloses an apparatus and process for, the electrolysis of an aqueous brine or alkali metal chlorine solution wherein separate tanks created by a diaphragm or permionic membrane have an electrical current provided to a platinum-coated anode in one tank and a platinum and steel cathode in the other tank to separate positive and negative ions in the separate tanks. The current is constant and the voltage across the cell serves to drive the process.
U.S. Pat. No. 3,755,114 issued to Hooker Chemical Corporation of New York, on the application of M. Tarjanyi, et al., discloses an apparatus and process for decreasing the metallic content of a solution wherein an electrolytic cell containing an electrolyte pumped therethrough has a positive electrode or anode and a negative electrode or cathode separated by a diaphragm or screen and an electrical current provided to the anode and cathode to separate positive and negative ions across the diaphragm. The screens prevent the discharge of particles through the outlet.
U.S. Pat. No. 5,569,370 issued to RMG Services Pty. Ltd., of Australia, on the application of R.A. Gomez, discloses a system for the recovery of metals from metal ores wherein the reactions are carried out in separate tanks, a first tank having anodes therein and a second tank having cathodes therein, the tanks being created by an electrically conductive wall. Power is provided to the anodes and cathodes to separate positive and negative ions in the separate tanks.
U.S. Pat. No. 4,909,913 issued to Toyo Soda Manufacturing Co, Ltd., of Japan, on the application of K. Fukuda, et al. , discloses, an apparatus and method for producing a metal salt by electrolysis in an electrolytic cell having separate compartments created by a diaphragm or membrane. An electrical current provided by source to the anode in one compartment and the cathode in the other compartment drives separate positive and negative ions into the separate compartments.
U.S. Pat. No. 4,804,523 issued to Bechtel Group, Incorporated, of California, on the application of J. Z. Abrams, et al., discloses a method for removing sulfur dioxide (SO.sup.2) from a flue gas in fossil fuel power plants wherein seawater is used as the source of magnesium (Mg) to produce magnesium hydroxide (Mg(OH).sub.2) absorbent by reaction with hydrated lime.
U.S. Pat. No. 5,814,224 issued to Institute Geokhimii, of Moscow, on the application of R. Khamizov, et al. , discloses a method for the desalination of seawater including magnesium separation by producing concentrated magnesium carbonate (MgCO.sub.3).
U.S. Pat. No. 4,483,753 issued to Vsesojuzny Institute, of the former USSR, on the application of I. V. Zabelin, et al., discloses a method of continuously extracting magnesium (Mg) from magnesium chloride (MgCl.sub.2) in a multiple cell flow apparatus.
While the previously disclose attempts at a precipitator comprising a container having a membrane or baffle which creates anodic and cathodic compartments and has a source of electrical current to charge the compartments so as to allow an electrolyte or aqueous brine solution to pass and the ions to be separated; and, further provide means to remove hydrogen and chlorine gases from the solution; and, still further a method using seawater as the source of magnesium (Mg) to produce magnesium hydroxide (Mg(OH).sub.2) precipitates and, still further separating ions (Mg++, etc.) contained in seawater by producing magnesium hydroxide (Mg(OH).sub.2) and hydrogen gas (H.sub.2) from magnesium (Mg) and water (H.sub.2 O) and magnesium (Mg) and water (H.sub.2 O) from magnesium oxide (MgO) and hydrogen gas (H.sub.2), none of these prior art patents teach applicants system for producing elemental magnesium (Mg) from seawater comprising: a cell having compartments separated by a pair of permeable membranes which create anodic and cathodic compartments, the anodic compartment having an anode therein and the cathodic compartment having an cathode therein; a space provided between the pair of membranes through which seawater is allowed to freely flow; a source of electric current connected to the anode and cathode to charge the compartments so as to allow seawater to pass from the space between and through the membranes and into said compartments whereby positive and negative ions are separated; means for collecting magnesium hydroxide (Mg(OH).sub.2) precipitate in the cathodic compartment; means for removing the collected magnesium hydroxide (Mg(OH).sub.2) precipitate from the cathodic compartment to means for reducing the collected magnesium hydroxide (Mg(OH).sub.2) to elemental magnesium (Mg) and water vapor, the reduction being effected by introducing hydrogen gas into the means for reducing wherein it contacts the collected magnesium hydroxide (Mg(OH).sub.2) precipitate. Still further none of these prior art patents teach applicant's method for producing magnesium hydroxide (Mg(OH).sub.2) precipitate and pure water from seawater comprising: providing a cell having compartments separated by a pair of permeable membranes which create anodic and cathodic compartments; providing a space provided between the pair of membranes through which seawater is allowed; to freely flow; passing electrical current through the Cell so as to allow seawater to pass from the space and through the membranes and into the compartments whereby positive and negative ions are separated; collecting magnesium hydroxide (Mg(OH).sub.2) precipitate that forms in the cathodic compartment; passing the magnesium hydroxide (Mg (OH).sub.2) precipitate to a magnesium reducer wherein it reacts with hydrogen (H.sub.2) gas to produce elemental magnesium (Mg) and water vapor.
Accordingly, it is seen that a need remains for a system and method for producing magnesium from sea water in an efficient manner. It is to the provision of such therefore that the present invention is primarily directed.